PalAeogeography and Stratigraphy of the Bohemian Cretaceous Basin (Czech Republic) – An Overview

Palaeogeographically, the area of the present day Bohemian Cretaceous Basin (BCB) formed a narrow Seaway between the North Sea Basin and the Tethys Ocean during the Late Cretaceous. The BCB together with adjacent Brannau-Regensburg Basin (Danubian Cretaceous Group) in Bavaria were a part of the peri-Tethyan shelf zone and contain a record of recurrent warm-temperate faunal assemblages with several incursions of Boreal fauna. The distribution of the coarse siliciclastic sediments demonstrate a significant control of stratigraphic architecture by tectonic activity and spatially variable sediment supply during the lifetime of the Bohemian Cretaceous Basin. Intra-basinal correlations of the BCB are based on application of both, non-biostratigraphic and biostratigraphic or eventostratigraphic methods. Nevertheless, some difficulties still appear with intra- and interbasinal correlation of the BCB (e. g., continental/marine, nearshore-offshore, entry of biomarkers or Boreal/Tethys correlations)

PalAeogeography and Stratigraphy of the Bohemian Cretaceous Basin (Czech Republic) – An Overview

Palaeogeographically, the area of the present day Bohemian Cretaceous Basin (BCB) formed a narrow Seaway between the North Sea Basin and the Tethys Ocean during the Late Cretaceous. The BCB together with adjacent Brannau-Regensburg Basin (Danubian Cretaceous Group) in Bavaria were a part of the peri-Tethyan shelf zone and contain a record of recurrent warm-temperate faunal assemblages with several incursions of Boreal fauna. The distribution of the coarse siliciclastic sediments demonstrate a significant control of stratigraphic architecture by tectonic activity and spatially variable sediment supply during the lifetime of the Bohemian Cretaceous Basin. Intra-basinal correlations of the BCB are based on application of both, non-biostratigraphic and biostratigraphic or eventostratigraphic methods. Nevertheless, some difficulties still appear with intra- and interbasinal correlation of the BCB (e. g., continental/marine, nearshore-offshore, entry of biomarkers or Boreal/Tethys correlations)

Trans-Atlantic correlation of Late Cretaceous high-frequency sea-level cycles

Previous studies of Cretaceous sedimentary rocks have used multi-proxy correlation methods to suggest eustatic change, modulated by the c. 400 kyr long eccentricity rhythm. Although numerous authors have inferred eustatic changes on shorter timescales, none have demonstrated synchronous sea-level changes in separate basins on different plates, thousands of kilometres apart. Our study integrates basin-scale, three-dimensional sequence architecture, molluscan biostratigraphy, and carbon-isotope chemostratigraphy to demonstrate synchronous sea-level changes in upper Turonian to lower Coniacian shallow-marine clastic successions in the Western Canada Foreland Basin, and the Bohemian Cretaceous Basin. Depositional sequences in both basins are plotted in a common time domain using an astronomically calibrated age model, allowing direct comparison. In both basins, at least seven major transgressive events can be shown to be synchronous within the limits of combined biostratigraphic and chemostratigraphic resolution. ‘Major’ and ‘minor’ sequences of late Turonian age appear to have been paced, respectively, by the long (c. 400 kyr) and short (c. 100 kyr) eccentricity cycles. In contrast, early Coniacian sequences evidence pacing by the c. 38 kyr obliquity rhythm. Stratal architecture suggests that sequences developed in response to eustatic changes of c. 14–20 m at average rates ranging 0.08 to >1.3 m/kyr. At a time of ‘warm greenhouse’ climate, sea-level change of this magnitude and timescale may not be explicable entirely as a result of thermal- and aquifer-eustasy, and hence glacio-eustasy may also have been a contributing factor

Comparative analysis of Czech and Spanish constitution with focus on differences caused by different organization of state and analysis of relevant legal terminology

The aim of this bachelor thesis is a comparation of the constitutional adjustment of the territorial organization of the Czech Republic and the Kingdom of Spain. The whole thesis is divided into several chapters. The opening section is dedicated to the outline of the historical evolution of constitutionality of the both countries and to the brief definition of the terms of the state administration and the local administration. The main part of the thesis deals with the analysis of the territorial organization of the Czech Republic and Spain. The emphasis is put especially on the inner organization of the territorial units and their authority. This part is followed by the comparative analysis, in which the systems of both the countries are compared. The whole thesis is concluded with a short language analysis and a Spanish-Czech glossary of which formation is the secondary aim of this thesis. The résumé is written in Spanish

Cobaltoan staurolite from Zambia

A cobalt-blue staurolite, containing 2.52 % CoO, is described from a locality east of Lusaka, Zambia. This locality is believed to be identical with that of lusakite described by Skerl and Bannister (1934). The mineral is pseudo-orthorhombic, with a = 7.876(1), b = 16.592(1), c = 5.652(1) Å, β = 90,00(2)°, a : b : c = 0.475 : 1 : 0.341, V = 738.63(14) Å³, Z = 2 ; D(m) = 3.737, D(x) = 3.758 g/cm³. It forms anhedral to subhedral grains up to 0.6 x 1.0 x 1.7 mm in size, which are associated with major magnetite (1.6 % CoO) and hematite. Other associated minerals include quartz, kyanite, ilmenite (2.3 % CoO), rutile, cobaltoan högbomite-4H (6.52 % CoO), cordierite (0.09 % CoO), sillimanite, Mg-chlorite, monazite, linnaeite, and pentlandite. — It is proposed that the name lusakite be retained for the cobaltoan analogue of staurolite with Co > Fe, Mg..On donne la description d'une staurotide bleue, contenant 2,52 % CoO, qui a été découverte dans un gisement situé à l'Est de Lusaka en Zambie. Il s'agit probablement du même gisement que celui de la lusakite, décrite par Skerl et Bannister (1934). Le minéral est pseudo-orthorhombique, avec a = 7,876(1), b = 16,592(1), c = 5,652(1) Å, β = 90,00(2)°, a : b : c = 0,475 : 1 : 0,341, V = 738,63(14) Å³, Z = 2 ; D(m) = 3,737, D(x) = 3,758 g/cm³. Il se présente en grains xénomorphes à, subautomorphes, de 0,6 x 1,0 x 1,7 mm, associés à la magnétite (1,6 % CoO) et à l'hématite abondantes. La paragenèse comprend également le quartz, le disthène, l'ilménite (2,3 % CoO), le rutile, högbomite cobaltifère-4H (6,52 % CoO), la cordiérite (0,09 % CoO), la sillimanite, la Mg-chlorite, la monazite, la linnéite et la pentlandite. — On propose de conserver le nom de lusakite pour un équivalent cobaltifère de la staurotide, avec Co > Fe, Mg.Čech František, Podondra Pavel, Vrana Stanislav. Cobaltoan staurolite from Zambia. In: Bulletin de Minéralogie, volume 104, 4, 1981. 12e assemblée générale de l'I.M.A. - Orléans – Juillet 1980. Deuxième partie : inclusions magmatiques / silicates / gemmes / « open session »

REE-Rich Turonian Phosphates in the Bohemian Cretaceous Basin, Czech Republic: Assessment as Source of Critical Elements and Implications for Future Exploration

Numerous phosphate occurrences are located in the Bohemian Cretaceous Basin (BCB) of the Czech Republic, within the Cenomanian–Turonian sequences. Small phosphate occurrences have been reported in the Upper Cenomanian, Lower Turonian, and Upper Turonian marine glauconitic siliciclasts. The phosphates are generally <1 m thick, present as phosphatized hardgrounds, nodules, coprolites, skeletal remains, phosphatized shells, peloids, sponges, and tube-fills, associated with black mudstone and other siliciclasts. Only recently the critical elements have been highlighted in these phosphates. The present study covers eight of these occurrences and provides information on petrography, mineralogy, and chemical composition of major elements, trace elements, and stable isotopes. The phosphate mineralogy is comprised of carbonate-fluorapatite, associated with quartz, glauconite, smectite, kaolinite, and pyrite. Most of the phosphates are rich in organic matter. The phosphate chemistry is dominated by P2O5, CaO, F, Na2O, SO3, and CO2. Minor amounts of SiO2, Al2O3, K2O, and MgO are found, related to quartz and alumino-silicate impurities. Evidence of fossil microbial structures is revealed. The indices derived from rare earth elements (REE) indicate phosphogenesis at various redox conditions, ranging from anoxic to oxic, whereas the carbon stable isotopes of the apatite suggest generally reducing conditions. The critical and other valuable elements found in these Mid-Cretaceous phosphates include P2O5 (18.9–26.76 wt. %), F (1.67–3.25 wt. %), REE (325–1338 ppm), Y (74–368 ppm), and U (10.4–37.9 ppm). The investigation of the Turonian phosphate occurrences show that those located at the base of the Bílá Hora Formation (earliest Turonian) are the most persistent in the southern margins of the BCB, and found in localities extending for about 200 km. They were developed at the onset of the Early Turonian global transgression and are strata-bound to the base of the Bílá Hora Formation. Future exploration for marine sedimentary phosphorites should focus on thicker and better developed deposits at the base of the Turonian sediments as the main target

REE-Rich Turonian Phosphates in the Bohemian Cretaceous Basin, Czech Republic: Assessment as Source of Critical Elements and Implications for Future Exploration

Numerous phosphate occurrences are located in the Bohemian Cretaceous Basin (BCB) of the Czech Republic, within the Cenomanian–Turonian sequences. Small phosphate occurrences have been reported in the Upper Cenomanian, Lower Turonian, and Upper Turonian marine glauconitic siliciclasts. The phosphates are generally 2O5, CaO, F, Na2O, SO3, and CO2. Minor amounts of SiO2, Al2O3, K2O, and MgO are found, related to quartz and alumino-silicate impurities. Evidence of fossil microbial structures is revealed. The indices derived from rare earth elements (REE) indicate phosphogenesis at various redox conditions, ranging from anoxic to oxic, whereas the carbon stable isotopes of the apatite suggest generally reducing conditions. The critical and other valuable elements found in these Mid-Cretaceous phosphates include P2O5 (18.9–26.76 wt. %), F (1.67–3.25 wt. %), REE (325–1338 ppm), Y (74–368 ppm), and U (10.4–37.9 ppm). The investigation of the Turonian phosphate occurrences show that those located at the base of the Bílá Hora Formation (earliest Turonian) are the most persistent in the southern margins of the BCB, and found in localities extending for about 200 km. They were developed at the onset of the Early Turonian global transgression and are strata-bound to the base of the Bílá Hora Formation. Future exploration for marine sedimentary phosphorites should focus on thicker and better developed deposits at the base of the Turonian sediments as the main target

Taxonomy And Stratigraphic Distribution Of The Ammonite Schloenbachia Neumayr, 1875 From The Bohemian Cretaceous Basin

Košťák, Martin, Sklenář, Jan, Mazuch, Martin, Čech, Stanislav (2019): Taxonomy And Stratigraphic Distribution Of The Ammonite Schloenbachia Neumayr, 1875 From The Bohemian Cretaceous Basin. Fossil Imprint 75 (1): 64-69, DOI: 10.2478/if-2019-0005, URL: http://dx.doi.org/10.2478/if-2019-000

Carbon isotope, greyscale and well-log data, Lower Turonian, Bohemian Cretaceous Basin

This dataset includes geochemical and geophysical data obtained from four boreholes in the western part of the Bohemian Cretaceous Basin (central Europe). The study interval covers the latest Cenomanian through lower Middle Turonian (c. 94.5 – 92.5 Myr ago). New data on the carbon-isotope ratios in bulk organic matter (d13Corg) from the cores 4523-A (Sedlec) and 4530-A (Horní Beřkovice) document the major carbon-isotope anomaly of the Oceanic Anoxic Event II and small-scale isotope excursions of the Lower Turonian interval. A greyscale-density profile of the core 4523-A and archive downhole resisitivity logs from two boreholes J-719670 and J-650704 provide high-resolution records of lithological variations of Milankovitch origin; these data were used to develop an astronomical time scale and interpret the phasing of orbital eccentricity in the study interval. A transient record of astronomical cyclicity was identified in major-element ratios (Si/Al) from the core Bch-1